I wish you were right, but that is not the case, sadly. I could give you several examples but here's one: there was a comment on HN a little while ago [1] about a spammer by the name of whitehallmedia. Every single email they send has an unsubscribe link. Clicking it (I used a test email account.) does not have the effect that one might expect.

[1] https://news.ycombinator.com/item?id=30405503